65 Valiant now gauges go full when ignition key turned or running

It is the IVR4 limiter. I cannot even see that led because it is so small and so up in the dash. The limiter is plugged into the gauge cluster board just as the original was. I was trying to make sure I didn't put it in backwards but it only goes in one way. So whatever way the way the factory intended on it being ground is the way it should be grounded. Whether it has a good ground or not I'm not sure. All the lights work on the cluster, so I'm assuming it's grounded ok. I put the ground lead of the voltmeter on the kick panel metal where there is usually some factory grounds when I was performing the test I did. I did test the temp sensor wire unplugged and it wasn't even reading a full volt with the RTE IVR4 plugged in. I don't know why that would happen. Maybe I didn't have the ground lead of the voltmeter grounded well, but I tried moving it to several spots to see if it changed. It may make sense to you'll here that when I put in a used original instrument voltage regulator that the gauges go full but when I remove it and put in the RTE IVR4 the gauges don't do anything. So it's just a matter of finding out where the problem is. How do I tell if the RTE IVR4 is properly grounded to the instrument cluster case? When the limiter is plugged in it's hard to test anything behind there. And if you have the cluster pulled out just a little to mess with it, you have to be careful because it's made to sorta wrap around the column tube and if you're not careful the plastic bezel could break at the corners. I can still get to the back with it installed easier than any other car I've got. It's just probing at it can be tricky. You don't know how many times I've had this cluster out. I tried to score an original gauge tester on EBAY but it went too high to make any sense of buying.